Automatic sprinkler



Aug. 2, M, LEW!S AUTOMATIC SPRINKLER Filed Aug. 20, 1936 Patented Aug. 2, 1938 UNiTED STATES PATENT OFFICE 2 Claims.

This invention has to do with automatic sprinklers such as are commonly employed for the purpose of automatically releasing a stream of water when a certain predetermined temperature has been reached.

At the'present. time, the fairly well crystallized practice in this field is to provide a fitting which constitutes the automatic sprinkler, and which fitting closes the end of a pipe which receives water under pressure. The fitting includes a closure which normally seals the end of the pipe against escape of the water, and this closure is usually held in position by an assembly of parts which ordinarily includes a glass or quartz tube or bulb that is filled with a liquid that is susceptible to the influence of heat, so as to fracture the bulb when a predetermined temperature has been reached.

This bulb and associated parts are held under pressure against the closure element, so that upon rupture of the bulb the pressure is relieved from the closure element and the Water pressure in the pipe is effective to blow the same off and provide the stream of water for fire fighting purposes.

An important phase of the present invention deals with the manner of assembling the frangible bulb in position holding the closure in place. This invention has in view as an important object the provision of a novel type of strut assembly which is readily collapsible upon rupture of the This strut member is also formed with a projection against which the frangible bulb is designed to bear. At the top a bridge engages the extremity of the strut element and the bulb, and pressure is placed on this bridge in the usual manner by a yoke and associated screw stem.

So long as the bulb remains intact, pressure is equally distributed through the said bulbs and strut member to eiTectively maintain the closure in sealing position. However, when a temperature has been reached which causes the bulb to fracture under influence of the material herein, the entire strut assembly collapses, releasing the closure.

Another important phase of the present invention is concernedwith thetube or bulb, which constitutes the critical element .inthe operation Heretofore. it has been the of the sprinkler.

practice to finally shape'these bulbs after the liquid has been introduced thereintoysuch final Tshaping usually involving the fusing of acapzon end portion to one end of a bulb. There are certain disadvantages attending this practice which are proposed to be obviated by the present invention.

In the first place, there is no method available for accurately testing the finally shaped container before the liquid is inserted. Hence, there is no assurance that the container will have the ability to withstand the stresses caused by the expansion of the'material in the bulb until the temperature which has been predetermined for rupture has been reached.

Another notable disadvantageous feature is that the fusing of a cap or end portion on the bulb is usually accompanied by the formation of a Wall structure at this point, which very often has the property of porosity to an undesirable degree. When this condition exists, the expansion of the liquid causes the escape of air through the porous structure, with the result that when the temperature at which the bulb is supposed to fracture has been reached, there is not a sufiicient amountof the material remaining in the bulb to cause the rupture.

Another important disadvantage which is inherent to the now known practice of finally shaping the bulb after filling is that it is practically impossible to secure any uniformity in the wall thickness. Under such conditions, any thinned or weakened portions of the wall are likely to cause a rupturing before the predetermined temperature has been reached, or a somewhat opposite condition may occur in that a small break or rupture will cause a leakage which will so reduce, the amount of material in the bulb as to prevent final complete rupture and subsequent fiow of water.

Bearing in' mind the above noted disadvantages, this invention proposes to obviate the same by providing a novel container or bulb element.

The invention has in view as an object, the provision of an automatic sprinkler Which includes a frangible element, of the character above noted, which is made in substantially conventional bottle shape or form, and which bottle is completely formed and shaped prior to the filling thereof by the liquid.

Another object of the invention is the provision of a frangible container or bulb, of the character above noted, which is readily adapted to receiving air' under pressure, in addition to the liquid material. This objective is readily obtained by availing of the bottle structure above noted, to-

gether with a closure element, such as a cork, 55

which may be forced downwardly into the b-ottle to build up pressure in the air therein.

Another more particular object in view is the provision of a bottle or container of the character above noted, together withappropriate means for hermetically sealing the opening through which the material is admitted. In carrying out this idea, wax or other sealing material may be applied to the stopper or cork after the latter has been properly positioned, and in addition a cap, preferably of soft metal; may be added to complete the seal.

By availing of the preformed bottle, in accordance with the above noted thoughts, it ispossible to test the bottle, and be sure the same,- has a properly uniform wall structure of a desired strength sufficient to withstand thestresses until reached. Accuracy in the quantity of liquid which is admitted to the bottle is alsoprovi-ded for, as Well asthe building up of pressure in the "ir; therein. f j Another importantadvantage attending this, practice is that the bottles or containers may be, manufactured much more cheaply than may the bulbs whi h have-heretofore "been used;

This invention also contemplates an arrangement in whichdifierently shaped bottles or containers are employed to indicate different, temperatures at, which the same will fracture.

, Various other more detailed objects and ad'- vantages will inpart become apparent, and in part be hereinafter stated, as the description of the invention proceeds.

"The-invention; therefore, comprises an automatic sprinkler consisting of a fitting formed with a socket which carries at one enda. closure for: the end of a pipe line. This closure is held in sealing position by a novel type of strut assembly iniwhich 'pressure' on the closure is appliedto a strut element on one side, and a franh ol win description andi'accoinpanying.

7 assembly including. a-.thin=disctmemb.er SIB;

""Anjimportant phase of the presentinvention isthe novel type of; bottle member whieh. isjin,- cluded in. th s rut asse bly as. the frangible.

p art, A bridge "engages, one end. of the strut n ra e ot e. pressure is applied: on.

hisq r dee frQ' lie i y h yol For arull'gmore complete understanding h pre n inv n ion. r f rence may e. had to .the s rew m mber which. is. c r.-

drawing wherein c Fi re. 1 is a. view in. si e elevationoff anau matic sprinkler, made in accordance with the precepts of. this invention,

' Figure 2" is an enlarged detailed view I in perspectiveofa strut element; and

' Figure 3' is a transverse section taken throughthe=frangible-bottle= 1 1 arries; at: one yenct a threaded; plug;.I..I., which is desi nedetojbe. threaded. into. the; extremity of y a pipe; (not. illustrated De; Suchia. pipe constie tlltfisa source ofzwat'er supplyandi ordinarily-.re.-..

ciiveswaten undenpressuree The. plug H, has. a. bore, indicated-at: I .2;.wl-1ich1is .clsed biv' a closure.

- be referred to as the closure.

the predetermined pressure has been preferably is of copper, and a backing member I 4.

As shown in the drawing, the disc member I3 is formed with a depressed portion which enters into the bore I2, and the backing member I4 has a complemental formation. Throughout the following description the assembly I4 and I3 will Member I4 is shaped to provide a boss I5 that is formed with a transverse notch l6. A strut member H has a knife edge at I8 which is received in the notch I6.

This strut member If? is also formed with a knife edge I9 at its upper end, and intermediate the ends thereof is struck therefrom a tab 20. This tab 20 may be formed by well known metal stampingoperations. The tab 20 is formed with a depression 2! which receives one end of a frangible bottle element indicated at 22. The particular manner, in. which the frangible bottle member Z2 is manufactured and filled with a liquidwill be hereinafter described in detail.

At. the. upper, end a bridge member 23 bears against. the. top, of the frangiblev bottle 22', andI this, bridge member 23 is formed with, a transverse notch 214. which receives the knife edge I'9'. The bridge member, on its upper surface isformed. with. a small recess or. depression '25, which receives. the pointed end 216 of a. threaded. stern. 2T that is carried by the yoke II). This; stem '27 is provided: with an operating member; in the. form of a hand wheel, indicated at.2 8.

Referring now more particularly to Figure. 3,, is. noted that the frangible bulb Z1 is. of. sub.- stantially acorn formation, although,. obviously, the invention is not to be limited: by the particular shape or size of this member. As briefly pointed out, the bottle 22. may be manufactured. by well. known glass. blowing operations, to pro..- vide a wall structure 29 which is substantially uniform throughout.

The bottle 22 has, an. open end at 30 which is. defined. by aneck 31;, A desired quantity of. some material, which. is susceptible, to the influence of heat toexpand'. and cause av fracture of the bottle when. a predetermined temperature has been reached. is placed inthe bottle 22. Carbontetrachlorid is one material which has been found suitable for such. use..

A. stopper or .cork. is. shown. at 32 as. being, pressedldownwardly inthe neck3 I. sufficiently far tahuild uplpressure in theair which may be contained in the bottle, in the spacewhich is not occupied by,- the Carbon. tetrachlorid. latter material, is; indicated. at3.3.. After the stopper or. cork 32. has, been properly positioned,. sealing. waxjas, indicated. at. 34, may. be. poured into the. neck. Qfithebottle to; effect a. hermetical. seal. A cap member is shown at 35 as'being positioned. over theneck 34., and. this; cap, member is preferably made. from. some; malleable. metal such. as. lead,, copper. or tin.

After the frangible bottle 21 has. been properly assembled. so; that. the same; will fracture. at. a.

certainpredetermined temperature, the-parts are assembled, asshownin Figure 1.. Whenthe all.- tomatic; sprinkler is. positiened. for service; by,

threadingtheplu Hi intozthe; endof; apipewhich Whenthis. temperature has been; reached. thei carbon:.tetrachlorid. inthe bottle 32:. will; expand:

and:cause=rupture.thereof.. :eWhenI thissruptuneoccurs, the.- sinrut assembly;

including; the-.simutimember I11 and bridge 23, wills. collapse, rtherebyrelieving the ,closnriefrom. any 75:

force or stress which opposes the pressure of the water in the pipe line, and such water pressure will, therefore, blow out the water pressure and provide a stream of water as contemplated.

While a preferred specific embodiment of the invention is hereinbefore set forth, it is to be clearly understood that I am not to be limited to the exact constructions illustrated and described, because various modifications of these details may be provided in putting the invention into practice Within the purview of the appended claims.

I claim:

1. In the manufacture of automatic sprinklers,

15 the method of forming a frangible vessel having a predetermined rupturing temperature which consists in placing an expansive material Within the bottle, building up a predetermined air pres sure in said bottle over said expansive material, and then sealing the bottle.

2. In the manufacture of an automatic sprinkler, the method of forming a frangible vessel having a predetermined rupturing temperature which consists in placing an expansive material in a bottle having an open neck, forcing a stopper downwardly in said open neck to build up a predetermined pressure on air in said bottle over the expansive material, and then sealing said stopper in said neck.

LEROY M. LEWIS. 

